In hot, dry climates such as the desert regions of the Southwestern United States, evaporative cooling systems are widely used for cooling dwellings and other architectural structures. These cooling systems are popular because of their relatively low cost compared with refrigeration cooling or air conditioning systems. Evaporative coolers operate on the principle of the cooling effect provided when water evaporates from a saturated pad through which warm, dry air from outside the dwelling is passed into the dwelling under control of a fan or blower.
For most effective use of an evaporative cooler, it is necessary to exhaust air continuously from the building and to bring fresh air into the building through the evaporation pads of the cooler. Generally, this is accomplished merely by leaving doors slightly ajar or opening windows in the rooms which are to be cooled. Because of security reasons and a general reluctance to leave doors and windows open, however, homes or buildings cooled by evaporative coolers often are closed up. This seriously impairs the operating efficiency of the evaporative cooler. Often purchasers of homes which have evaporative coolers in them do not know that it is necessary to have a continuous air flow into and out of the building or home to obtain maximum cooling. This is because this type of operation is in direct contrast to achieving maximum cooling efficiency with refrigeration type air conditioning systems in which it is desirable to have the home or building closed up as tightly as possible.
As a consequence, it is desirable to provide some means for obtaining maximum cooling efficiency from an evaporative cooler with a minimum of effort on behalf of the homeowner or building owner where an evaporative cooler is used. It further is desirable to obtain maximum operating efficiency of evaporative coolers without compromising the security of the dwelling or building in which an evaporative cooler is used. Finally, it is desirable to provide a means for obtaining maximum efficiency from an evaporative cooler which is simple to install and trouble-free in operation.